Compiling against libc++ on 10.6 and using the binary on 10.7

[Ryan Schmidt]

On Mar 24, 2018, at 01:33, Mojca Miklavec wrote:

> On 24 March 2018 at 02:57, Ryan Schmidt wrote:
>> On Mar 23, 2018, at 05:35, Mojca Miklavec wrote:
>> 
>>> I'm compiling some command-line tools and I tried to aim supporting
>>> 10.6 (asking 10.6 users to grab libc++ from somewhere if they are
>>> desperate enough to want to use the binaries).
>>> 
>>> I compiled against libc++ provided by MacPorts and asked a user to
>>> test that binary on 10.7 (I would need to install one somewhere
>>> first). Apparently the binaries did not work there, probably because
>>> libc++ installed on 10.6 is newer than the one Apple shipped with
>>> Lion. I need to double-check if that's in fact the case (he could have
>>> mixed some binaries), but I just wanted to ask if there's some
>>> workaround to that.
>> 
>> I suppose that is a possible reason why it wouldn't work. Seeing the actual error message might help diagnose.
> 
> $ ./foo --version
> dyld: Symbol not found: __ZNSt12length_errorD1Ev
>  Referenced from: /path/to/./foo
>  Expected in: /usr/lib/libc++abi.dylib
> in /path/to/./foo
> Trace/BPT trap: 5

Well, I don't know. Maybe somebody else does.


>>> (Maybe I should then compile on Lion, grab the 10.6 SDK from
>>> somewhere, compile against 10.6 SDK and link against libc++ from Lion?
>>> I don't particularly like this idea though. I could use the "cxx11
>>> 1.1" trick, but I hate to have to relink all the binaries at the end.
>>> None of that is ideal.)
>> 
>> Do you really need the 10.6 SDK? You're supposed to be able to use the latest SDK, and set MACOSX_DEPLOYMENT_TARGET to the lowest OS version you want to run on.
> 
> I don't know. I clearly remember that long long time ago I would
> compile on 10.6 with MACOSX_DEPLOYMENT_TARGET set to 10.5, but until I
> added the -isysroot the binaries would not work on 10.5. Usually
> autotools figure out that they could use a function that exists in
> that newer SDK and then the binary no longer works. If I compile
> against 10.7: would you do it on a 10.6 or a 10.7 VM? If I compile
> against the 10.7 SDK I would indeed get that older libc++ library that
> should then hopefully work everywhere.

I guess Apple's instructions to use the latest SDK only apply to Mac-specific software that has been written to understand the SDK situation, and autotools-based projects might not understand it.

I guess then you should compile on any OS version, 10.6 or later, setting MACOSX_DEPLOYMENT_TARGET to 10.6 and using the 10.6 SDK from Xcode 3.2-4.3.3, with 10.7's libc++ copied into it.